cur_num = 0
active = True
while active:
    if cur_num <= 10:
        cur_num = cur_num+1
        print(cur_num)
    else:
        active = False
print('+++++++++++++++++++++++++')

cur_num = 0
while True:
    if (cur_num <= 20):
        cur_num += 1
        print(cur_num)
    else:
        break

print('+++++++++++++++++++++++++1')
cur_num = 0
while True:
    cur_num += 1
    if (cur_num <= 20):
        if (cur_num % 2 == 0):
            print(cur_num)
        else:
            continue
    else:
        break
print('+++++++++++++++++++++++++2')
cur_num = 0
while cur_num < 20:
    cur_num += 1
    if (cur_num % 2 == 0):
        continue
    else:
        print(cur_num)

print('+++++++++++++++++++++++++3')
pets = {'cat', 'dog', 'rabbit', 'wolf', 'dog', 'cat'}
print(pets)
v_str = 'cat'
while v_str in pets:
    pets.remove(v_str)
print(pets)
